package com.seckill.service.impl;

import com.seckill.dao.SeckillDao;
import com.seckill.dao.SuccessKilledDao;
import com.seckill.dto.Exposer;
import com.seckill.dto.SeckillExecution;
import com.seckill.entity.Seckill;
import com.seckill.entity.SuccessKilled;
import com.seckill.enums.SeckillStateEnum;
import com.seckill.exception.RepeatKillException;
import com.seckill.exception.SeckillCloseException;
import com.seckill.exception.SeckillException;
import com.seckill.service.SeckillService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.DigestUtils;

import java.util.Date;
import java.util.List;

/**
 * Created by lsy on 2017/5/17.
 */

@Service
public class SeckillServiceImpl implements SeckillService {

    private Logger logger= LoggerFactory.getLogger(this.getClass());

    @Autowired
    private SeckillDao seckillDao;

    @Autowired
    private SuccessKilledDao successKilledDao;

    //用于混淆md5
    private final String slat ="wqdnaon!@#!%oP51!@%BF!@%nfpUGFInodfhYAOVFBhfUFqmpq5qDQ89WD4Q1fA8V";



    @Override
    public List<Seckill> getSeckillList() {

        return seckillDao.queryAll(0,4);
    }

    @Override
    public Seckill getById(long seckillId) {
        return seckillDao.queryById(seckillId);
    }

    @Override
    public Exposer outSeckillUrl(long seckillId) {
        Seckill seckill=seckillDao.queryById(seckillId);
        if (seckill==null){
            return new Exposer(false,seckillId);
        }

        Date startTime=seckill.getStartTime();
        Date endTime=seckill.getEndTime();
        Date nowTime=new Date();
        if (nowTime.getTime()<startTime.getTime()
                ||nowTime.getTime()>endTime.getTime()){
            return new Exposer(false,seckillId,nowTime.getTime(),startTime.getTime(),endTime.getTime());
        }

        String md5=getMD5(seckillId);
        return new Exposer(true,md5,seckillId);
    }


    @Override
    @Transactional
    /**
     * 使用注解控制事物的优点
     * 1.开发团队达成一致,明确编程风格
     * 2.保证事务方法的执行时间尽可能短,不要穿插其他网络操作或则剥离到方法外面
     * 3.不是所有的方法都需要事务,如一条修改操作或只读操作
     */
    public SeckillExecution executeSeckill(long seckillId, long userPhone, String md5) throws SeckillException, RepeatKillException, SeckillCloseException {

        if (md5==null|| !md5.equals(getMD5(seckillId))){
            throw new SeckillException("seckill data rewrite");
        }
        //执行秒杀逻辑:减库存 + 记录购买行为
        Date nowTime=new Date();


        try {
            int updateCount=seckillDao.reduceNumber(seckillId,nowTime);
            if (updateCount <= 0) {
                //没有更新记录
                throw new SeckillCloseException("Seckill is closed");
            } else {
                //记录购买行为
                int insertCount = successKilledDao.insertSuccessKilled(seckillId, userPhone);
                //唯一的seckillId和userPhone
                if (insertCount <= 0) {
                    //重复秒杀
                    throw new RepeatKillException("seckill repeated");
                } else {
                    //秒杀成功
                    SuccessKilled successKilled = successKilledDao.queryByIdWithSeckill(seckillId, userPhone);
                    return new SeckillExecution(seckillId, SeckillStateEnum.SUCCESS, successKilled);

                }
            }
        }catch (SeckillCloseException e1){
            throw e1;
        }catch (RepeatKillException e2){
            throw e2;
        }catch (Exception e){
            logger.error(e.getMessage(),e);
            //所有编译异常
            throw new SeckillException("seckill inner error:"+e.getMessage());
        }

    }





    private String getMD5(Long seckillId){
        String base =seckillId+"/"+slat;
        String md5= DigestUtils.md5DigestAsHex(base.getBytes());
        return md5;
    }
}
